Along with the development of the network, products and services that provide an additional value when they are connected to the network are becoming available, for example, a surveillance camera and a video recorder, a car navigation system and a map delivery server, and a home/building facility devices and their administrative terminal.
Network connection can lead to threats such as data interception/tamper or identity fraud. This increases the need for loading a de-facto-standard cryptographic authentication communication function which uses a public key certificate such as SSL (Secure Socket Layer)/TLS (Transport Layer Security) or IPSec (IP Security) on a device, a terminal, or a server.
When practicing cryptographic authentication communication, a key and a certificate which are necessary for encryption and authentication must be set for the device. Such certificate must include the host name and IP address of the device.
As in Patent literature 1, when storing a private key and a certificate in a device at the time of manufacture, information such as an IP address or host name that are not determined yet at the time of device manufacture cannot be stored in the certificate.
As a result, in a case where a device communicates by using a private key and a certificate (for example, when the device has an SSL server function), when the device is accessed by the browser by https communication, the browser displays a message “the access target device may be a fraud”. This is due to the following reason. The host-name-corresponding portion of the head portion of the URL specified by the browser does not coincide with the host-name-corresponding portion which is stored at the CommonName of the subject name of the certificate sent from the device in question. As a result, the browser cannot discriminate if the device is the authentic device specified by the host name.
Meanwhile, in order to include the device identification information such as the host name in the device certificate at the time of system construction, after the device identification information is set in the device, the device needs to perform a certificate generation process, and the device identification information needs to be set in the certificate.
If the device administrator is allowed to perform a procedure of obtaining the certificate from the certificate authority and setting the obtained certificate in the device, the certificate including the host name can be set in the device easily. In general, however, it is not allowed to practice a complicated procedure requiring a manual operation for a facility device which is to be installed in a home/building or for an information appliance marketed for home use.
A network camera as one type of facility device comprises a function of automatically generating a certificate including a host name at the time of system construction. The certificate is, however, a self-signed certificate (SelfSign Certificate). Unlike a certificate whose authenticity can be verified based on a certificate separately issued by a certificate authority, for a self-signed certificate, no certificate exists which is issued by a certificate authority to verify the authenticity. For this reason, when a self-signed certificate is to be used, it is necessary to deliver the self-signed certificate to a verification side system by using a secure offline transmission means, and to install the self-signed certificate in the verification side system as a trustworthy certificate.